- http://www.catb.org/~esr/writings/taoup/
- http://www.catb.org/~esr/writings/taoup/html/
- https://en.wikipedia.org/wiki/The_Art_of_Unix_Programming
- ISBN … – paper, PDF, EPUB – I like EPUB best, because I have a constant correlation of the text I am reading right now to its place within the hierarchical TOC (I had to regenerate the TOC within Calibre though)